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THE VEGETATION AND FLORISTIC COMPOSITION ALONG THE BRAHMAPUTRA RIVER AND THE BRAHMAPUTRA VALLEY, ASSAM, INDIA
REPORT
Submitted by
Pranab Bujarbarua Department of Botany
Handique Girls’ College, Guwahati
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CONTENTS
Chapter 1: Introduction ………. 5
Chapter 2: Vegetation and Forest Type ………. 9
Chapter 3: Conspectus of the Flora of Brahmaputra Valley ………. 16
Chapter 4: Significance of the Flora ………. 21
Chapter 5: Utility of the Floristic Diversity ………. 22
Chapter 6: High Priority Taxa ………. 24
Chapter 7: Threats ………. 26
Chapter 8: Problems of Forest Management in the Brahmaputra Valley………. 29
Chapter 9: Discussion ………. 32
Bibliography ………. 37
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List of Appendix:
Appendix I - Floristic diversity of the national parks of Assam 43 Appendix II - Floristic diversity of the Islands of Brahmaputra river 44 Appendix III - Floristic diversity of Assam worked out by different workers 45 Appendix IV - Comparisons of Evergreen species distributed in Brahmaputra
and Barak valley 46 Appendix V - Endemic plant taxa of Assam 49 Appendix VI - List of primitive families and genera and representative 53
species in the Brahmaputra valley. Appendix VII - Economically important plants of Brahmaputra valley 55 Appendix VIII - Wild relatives of cultivated plants found in the Brahmaputra 57
valley Appendix IX - Rare, Threatened and Endangered Plant Taxa of Assam 59
Annexure
Annexure I - List of Orchids of the Brahmaputra valley 61
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Photo Plates
1. Tree and Timber yielding plants
2. Economically important plants
3. Medicinal plants
4. Parasitic angiosperms
5. Orchids
6. Potential floricultural plants
7. Wild edible fruits
8. Other common plants
9. Invasive species
10. Gymnosperms and ferns
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Acknowledgement
The report ‘The vegetation and floristic composition along the Brahmaputra river
and the Brahmaputra valley, Assam, India’ has been submitted under the contract
agreement between the undersigned and the Tetratech. I am deeply indebted to Dr. K.K.
Dwivedi, CEO, AIFRERMIP and Mr. S. K. Choudhury, Officer in Charge, Tetratech, Guwahati
and who have given me the opportunity to work under assignment. It gives me great
pleasure to express my deep sense of gratitude to Dr. Dwivedi for his useful suggestions. I
am also thankful to Dr. Udayan Borthakur, Co-ordinator of the project for his fruitful
discussions and encouragement throughout the study.
I acknowledge the help and suggestions of the villagers of Mulai Kathoni, Jorhat,
forest officials of Panidihing bird sanctuary, Garampani WLS and Mr. Joynal Abedin (Benu
da) for his suggestions during my visit to Dibru-Saikhowa BR.
Last but not least my heartiest thanks to Dr. Jayanta Das for their fruitful
suggestions. Some of the photographs used in the report are taken from Dr. A.K. Baishya,
Dr. P.J. Bora, Dr. Bandana Nabis Das and Mrs. Prabhali Doley. I acknowledge their help in
this regard.
Pranab Bujarbarua Assistant Professor
Department of Botany Handique Girls’ College,
Guwahati
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Chapter 1
INTRODUCTION
Northeast India consisting of eight states of Assam, Arunachal Pradesh, Manipur,
Meghalaya, Mizoram, Nagaland, Tripura and Sikkim comprising an area of about 2, 62, 179
Km2 is known for its rich biological and cultural diversity. Based on its physiography and
biological composition, the region can broadly be categorized into the Eastern Himalaya,
Northeast hills and Brahmaputra plains. Its unique location at the confluence of the Indo-
Malayan, Indo-Chinese and Indian biogeographical regions coupled with its physiography
has generated a profusion of habitats, which harbors diverse biota with high level of
endemism. The region is part of Himalaya and Indo-Burma biodiversity hotspots, two of 34
such hotspots in the world (Mittermier, 2004). It is also home of over hundred ethnic
communities and a large percentage of the population is dependent on traditional natural
resource-based livelihoods. Northeast region is characterized by high rainfall and humidity.
This along with varied altitudinal gradients influence the climate that ranges from tropical
plains to temperate and alpine hills. These diverse climates supports almost all types of
vegetation from cultivated plants to grasslands, meadows, marshes, swamps, scrubs, mixed
deciduous and humid evergreen forest, temperate and even alpine vegetation.
Assam, one of the sister states of Northeast India is regarded as biogeographical
gateway for much of India’s biological resources. Nestling between the eastern Himalayan
foot hills and the Patkai and Barail ranges of hills, the state is one of the largest north
eastern states of India. It is characterized by distinct habitats, landscape, broad valleys and
hills. Though largely plain, the Barail range is mountainous. Both sides of this range are the
Brahmaputra and Barak valleys. Situated between 24o2’- 27 o6’N latitude and 89o8’-96o E
longitude, the political boundary of Assam extends to an area of 78,523 sq km of which total
forest area is about 27,673 sq km that is about 35.28% of the total geographical area of the
state (Forest Survey of India, 2011). This area excludes the unclassed state forest which is
approximately 5865 sq. km. The occurrence of heterogenic physiography coupled with
varied climatic conditions on and around the state has made the vegetation luxuriant and
diverse that support unique flora and fauna. The variations in forest types and their
vegetation composition in Assam occur mainly due to the range of climatic conditions and
to certain extent due to local edaphic factors (Baishya, 1999).
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The mighty river Brahmaputra traverse the state from east to west covering a
distance of about 1300 km thereby separating the sub-himalayan region of Assam from the
southern parts and forms the gorgeous Brahmaputra valley with an elevation of about 122m
at Sadiya the eastern most and 30m at Dhubri the western most part of the valley. The
uniqueness of Brahmaputra river system lies in its glacial origin, location in a highly seismic
zone, heavy and intense rainfall resulting in flash flood, high sedimentation rate and an
intricate link with the ecology of the beels (wetlands) in the plains.
Map 1: Map of Assam showing topographic feature & River Network (Source: Assam: National Disaster Risk Reduction Portal)
Brahmaputra valley being the largest plain in the northeast region and has a great
significance not only for agriculture and industry of the region but also for its rich vegetation
preserved in the various protected areas i.e. biosphere reserves, national parks and wildlife
sanctuaries etc. There are 5 national parks, 20 wildlife sanctuaries and a number of reserve
forests are present in this valley, of which two national parks viz. Manas and Dibrusaikhowa
have also been categorised as biosphere reserves. The forest types are mostly tropical which
harbours a rich pool of biodiversity.
The rich flora of the area has been the centre of attraction for various botanists since
early 19th century which began with the famous Assam tea delegation comprising N. Wallich
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(1820-1832), W. Griffith (1848), Robinson (1841) provided some floristic account of the
region. Some of the earlier contributors to the flora of Assam are Carter (1921), Hooker et al
(1872-1892), Kanjilal (1934-40), Bor (1940), etc. Baishya (1999) gave a detailed account of
the florstics of Assam. Chowdhury (2005) compiled a detail account on the flora of Assam.
More recently, Barooah and Ahmed (2014) made a comprehensive checklist of the
angiosperms and gymnosperms of the state.
Flora of Assam by Kanjilal et al was the beginning of botanical studies by Indian
Botanists. Subsequently, a number of Botanists contributed to the understanding the flora
of the state (Rao & Verma 1969, Kar & Panigrahi 1963, Jain & Hajra 1975, Rao 1974, Islam
1990, Sarmah 1989 and Sas Biswas et al 1990). Many workers have attempted the floristic
studies of different districts as well as the protected areas of the state (Gogoi 1976, Barua
1978, Hajra 1978, Sarmah 1989, Barua 1992, Sarkar 1993, Singh 1993, Nath & Choudhury
1994, Bora 1999, 2001, Barooah & Borthakur, 2003, Bujarbarua 2004, Begum, 2010, Begum
et al., 2010, Nath, 2012, 2015 etc.). Bhagawati et al (2006) made an effort to prepare the
biodiversity status of the state of Assam along with the strategy action plane for
conservation.
Although the state has been well explored floristically, yet there are areas with
ample scope of floristic study particularly protected areas of the state. Moreover, a detailed
account of the flora of the present state of Assam is yet to be brought out. Considering the
vastness and ecologically diverse area, there is plenty of scope to increase these numbers as
many areas are still unexplored or underexplored. One such most important area of the
state is the river bank vegetation. The river bank vegetation, ecologically termed as riparian
is highly dynamic vegetation. River’s riparian zone acts as a bridge between terrestrial and
aquatic habitat. These areas are represented by a particular type of vegetation that grows
along the sides of rivers under the influence of a waterway, such as rivulet banks or
riverbanks. Riparian i.e. river bank vegetation at a particular location and time results from
interactions between the physical conditions created by geomorphic and hydrologic
processes in the stream channel and responses by the plants (La Fayette & DeBano, 1990).
The present report is being prepared with an aim to work out the
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- vegetation types and flora along the course of the river Brahmaputra river.
- documentation agro biodiversity, invasive species, grassland habitats, plants of
economic and other uses in the areas along the Brahmaputra river, and
- screening of the rare, threatened, endangered as well as the endemic taxa.
Work plan:
The study was primarily based on the literature survey. Moreover, field visits to the
various locations in the protected areas along the river Brahmaputra and other riparian
locations along the river was also conducted to validate the secondary data.
Sl no. Component 1st Month 2nd Month 3rd Month
1 2 3 4 1 2 3 4 1 2 3 4
1 Literature Survey
2 Field Visit
3 Data compilation
4 Report Preparation
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Chapter 2
VEGETATION AND FOREST TYPE
The geographical areas of the state lies in the transitional zone of Indo-Malayan and
Indo-Chinese and India, along with two migratory route of birds - the Central Asian flyway
and East Asian-Australian flyway which enriches floristic and faunal composition of the
region (Islam & Rahmani, 2004). The major types of plant communities found in the state
can be grouped under Moist Evergreen Forest, Moist Semi-Evergreen, Moist and Dry
Deciduous forest, Hydrophytes in vast stretches of wetlands (riparian belts, swamps and
marshes), Bamboo brakes, Scrubland and Grass land (both wet and dry). The forest types of
northeast India including the state of Assam have already been described by Champion and
Seth (2005). The state of Assam falls in the tropical climate belt in the northeastern region
of India (Srivastava et al. 2002) and maximum forest area of the state included under
tropical moist deciduous type (Agarwala 1990). In general the vegetation of Assam is
primarily tropical type that covers large areas and embraces evergreen, semi evergreen,
deciduous forests and grass lands. Stretches of riparian forest along the bank of rivers are
also very prominent. The variations in forest types and their vegetation composition in
Assam occur mainly due to the varied physiographic, edaphic conditions and range of
climate. As there are not much altitudinal variations in the plains particularly in the
Brahmaputra valley, it has little significance in determining the forest types of Brahmaputra
valley.
It may be mentioned here that majority of the protected areas of the state are
situated at the Brahmaputra valley and most of these are either well explored or under
explored floristically. It is thus obvious that the vegetation and forest types of these
protected areas have already been worked out. From all such available sources and personal
observation, the vegetation and forest type along the Brahmaputra river in Assam may be
considered as tropical moist evergreen, tropical semi evergreen, moist deciduous forest,
Grass land and savannah, wetlands and swamps, riparian forest and degraded lands. A brief
account of these forests given as follows -
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2.1. Tropical Moist Evergreen Forests:
The moist evergreen forests is characterised by the stratification of the plants into
different storeys. These type of forests are prevalent in specific areas of upper Assam in the
districts of Tinsukia, Dibrugarh, Sibsagar, Jorhat and in few places of Dhemaji and
Lakhimpur. Luxuriant and gregarious growth of broad leaved lofty tree species of
angiosperms along with a number of tree ferns, epiphytes including orchids are the
characteristic features of these forests. Although it is difficult to demarcate easily various
storeys in these forests, but a few tall trees along with some medium sized form the canopy
and merge with large shrubs intermingle with climbers and dense undergrowth of low
shrubs and herbs (Chowdhury, 2005). Rowntree (1954) termed these forests as
Dipterocarpus – Mesua formation.
The giant Dipterocarpus retusus attaining a height of over 40m is the most
prominent species in the top storey. The associated species are Alianthus grandis, Altingia
excels, Artocarpus chama, Artocarpus lakoocha, Cinnamomum bejolghota, Mesua ferrea,
Michelia champaca, Phoebe cooperiana, Shorea assamica, Tetremeles nudiflora etc.
The common species composed of middle storey are Actonodaphne angustifolia, A.
obovata, Aglaia hiernii, Antidesma bunius, Aquilaria malaccensis, Baccaurea ramiflora,
Beilschmiedia brandisii, Callicarpa arborea, Canarium strictum, Castanopsis indica,
Chukrasia tabularis, Cinnamomum glanduliferum, Cryptocarya floribunda, Dillenia indica,
Diospyros variegate, Dysoxylum procerum, Elaeocarpus sp, Engelhardtia spicata, Evodia
meliaefolia, Ficus benjamina, Flacourtia jangomas, Garcinia acuminate, Garcinia kydia, G.
xanthochymus, Gynocardia odorata, Litsea monopetala, L. glutinosa, Macaranga
denticulate, Magnolia griffithii, Magnolia hodgsonii, Mesua ferrea, Mesua assamica (Kayea
assamica), Michelia baillonii, Olax acuminate, Persea bombycina, Phoebe goalparensis,
Quercus milroyii, Sapium baccatum, Sterculia guttata Symplocos ferruginea, Syzygium
cumini, Terminalia myriocarpa, Vatica lancaefolia. etc.
The lower storey is often found in association of sparsely distributed species viz.
Alangium chinensis, Aphanomixis polystachya, Camellia caudata, Croton roxburghii, Dillenia
indica, Dysoxylum binectariferum, Litsea assamica, Litsea salicifolia, Mallotus philippinensis,
Saurauia panduana, Symplocos ferruginea, Syzygium oblatum, Turpinia nepalensis,
Zanthoxylum rhetsa, etc.
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The common shrubs in these forests are Actephila excels, Antidesma acidum,
Antidesma acuminatum, Ardisia paniculatum, Boehmaria malabarica, Brassiopsis
glomerulata, Callicarpa longifolia, Chloranthus officinalis, Dendrocnide, sinuata, Euonymus
attenuates, Glochidion assamicum, Morinda angustifolia, Wendlandia tinctoria, etc.
The lianas, vines and stragglers often show gregarious growth mingled with the
species of plants in the storeys associated with a number of shrubs. The common species
found are – Clematis acuminata, Celastrus monosperma, Cryptolepis sinensis, Desmos
cochinchinensis, Dioscorea esculenta, Erythropalum scandens, Fissistigma bicolour, Gnetum
montanum, Hoya acuminata, Jasminum nervosum, Naravelia zeylanica, Tetrastigma
dubium, Tetracera indica, etc. Apart from these a number of climbers developed terrestrial
but become epiphytic on trees and shrubs or creeping in nature. The common species are
Piper peepuloides, P. sylvaticum, Pothos cathcartii, Raphidophora sp. etc.
2.2. Tropical Semi-evergreen forests:
Semi-evergreen forests are mainly confined to along the north and south banks of
river Brahmaputra; Bura-pahar and the projection of Karbi-Anglong towards Brahmaputra
(Chowdhury, 2005). This forest is mainly dominated by medium or short trees where large
numbers of shrubs are entangled by lianas and stragglers. Ground vehetation is occupied by
bulbous, rhizomatus plants scattered in association with herbaceous angiosperms; ferns and
fern allies. Moreover, these forests are adorned with luxuriant growth of several epiphytic
plants primarily orchids and ferns. Besides, large bamboo and cane thickets are found along
the edges of forests and in degraded forest as secondary growth. The common species
found in the forests are Actinodaphne obovata, Aesculs assamica, Albizia procera,
Anthocephalus chinensis, Antidesma bunius, Aphanomixis polystachya, Artocarpus chama,
Baccaurea ramiflora, Beilschmiedia fagifolia, Bauhinia purpurea, Bischofia javanica, Bridelia
retusa, Castanopsis armata, Cinnamomum bejolghota, Duabanga grandiflora, Dysoxylum
binectariferum, Elaeocarpus floribunda, E. sphaericus, Engelhardtia spicata, Gmelina
arborea, Lagerstroemia parviflora, Litsea glutinosa, L. monopetala, L. salicifolia, Macaranga
denticulate, Talauma hodgsonii, Mallotus ferrugineus, Mangifera sylvatica, Michelia
champaca, Persea villosa, Stereospermum personatum, Syzygium cumini, S. oblatum,
Tamarindus indica, Terminalia chebula, Terminalia myriocarpa, Trewia nudiflora, Toona
ciliate, Vatical lancaefolia, Wendlandia grandis, etc.
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Shrubby species in these forests composed of mainly Antidesma roxburghii,
Chloranthus elatior, Euonymus attenuates, Ficus subulata, Glochidion assamicum, Grewia
denticulata, Mussaenda roxburghii, Mycetia longifolia, Psychotria Montana, Randia spinosa,
Rhamnus nepalensis, Saprosma ternatum, Solanum torvum, Vitex trifolia, Zizyphus
mauritiana, etc.
The common species among the lianas, stragglers and vines are Ampelocissus
barbata, Argyreia roxburghii, Bauhinia vahlii, Cissus rependa, Derris ferrginea, Dioscorea
bulbifera, Entada pursaetha, Erythropalum scandens, Merremia umbellata, Naravelia
zeylanica, Paederia foetida, Pothos scandens, Rhaphidophora decursiva, Rubia cordifolia,
Smilax ochreata, Vitis planicaulis andexotic climber Mikania micrantha.
The under growth composed of several annual and perennial herbs viz. Ageratum
conyzoides, Alocasia odora, Biophytum sensitivum, Begonia palmata, Coffea benghalensis,
Crotalaria pallid, Curculigo orchioides, Elatostema integrifolia, Flemingia lineata, Globba
clarkei, Impatiens tripetala, Justicia adhatoda, Justicia japonica, Leea aequata, Mollugo
pentaphylla, Ophiorrhiza mungos, Panicum auritum, Phlogacanthus curviflorus, Polygonum
auriculatum, Saccharum ravennae, Sida rhombifolia, Solanum nigrum, Spilanthes paniculata,
Stachytarpheta jamaicensis, Synedrella nodiflora, Thysanolaena maxima, Urena lobata,
Vernonia cinerea, etc. along with ground orchids Arundina graminifolia, Calanthe angusta,
Geodorum densiflorum, Goodyera procera, Tainia latifolia, etc.
2.3. Moist Deciduous forest:
The moist deciduous forest may be categorised into Shorea (Sal) forest and mixed
moist deciduous forest. The large parts of the lower Brahmaputra valley particularly in
districts of Nagaon, Morigaon; in alluvial plains of south and north Kamrup, Darrang,
Sonitpur, parts of Nalbari, Barpeta, Dhubri, heavy alluvial plains of Kokrajhar, Bhabor and
Terai regions of Kokrajhar and Goalpara districts and parts of Karbi Anglong and Dima Hasao
are covered with Sal forest. Rowntree (1954) described these Sal forest under Shorea-
Schima-Lagerstroemis association while Bor (1938) named Shorea-Schima-Stereospermum
formation. The most conspicuous naturally growing Shorea robusta in moist Sal forest is
found near Chandubi in Kamrup district and also in the district of Dhubri, Kokrajhar,
Goalpara and some parts of Kamrup district.
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The mixed moist deciduous type of forest occupies a large area in both Brahmaputra
and Barak valleys at the foot hills of Lakhimpur, Dhemaji, Karbi-Anglong and Dima Hasao
districts. Tree species particularly Adina cordifolia, Albizia procera, Artocarpus chama,
Beilschmiedia fagifolia, Bridelia retusa, Butea monosperma, Callicarpa arborea, Careya
arborea, Caryota urens, Dalbergia ssissoo, Duabanga grandiflora, Dysoxylum binectariferum,
Engelhardtia spicata, Ficus benjamina, Hydnocarpus kurzii, Garcinia paniculata, Garuga
pinnata, Gmelina arborea, etc. occupy the upper storey.
The predominant species in the lower storey of these forests are Actephila excels,
Antidesma acidum, A. bunius, Bauhinia acuminata, Bischofia javanica, Buddleia asiatica,
Caesalpinia bonduc, Cinnamomum bejolghota, Litsea salicifolia, Premna benghalensis, Rhus
semialata, Wrightia tomentosa etc. Dendrocalamus hamiltonii, D. strictus, Melocanna
baccifera are common species of bamboo found in these forests.
2.4. Riverine forest:
River bank vegetation, ecologically termed as riparian is highly dynamic vegetation.
River’s riparian zone acts as a bridge between terrestrial and aquatic habitat. These areas
are represented by a particular type of vegetation that grows all over the evergreen and
semi evergreen zones of the state along the sides of rivers under the influence of a
waterway, such as rivulet banks or riverbanks. Generally in this type of forests commonly
found tree species are Dillenia indica, Anthocephalus indicus, Semecarpus anacardium,
Albizia lebbek, Dalbergia stipulacea, Bischofia javanica, Duabanga grandiflora,
Lagerstroemia speciosus and Bombax ceiba. The middle storey of these forests are generally
occupied by Altingia excels, Albizia lucida, Artocarpus lakoocha, Alstonia scholaris, Cedrela
toona, Dalbergia assamica, Pterospermum acerifolium. Species viz. Alpinia nigra,
Ammomum aromaticum, Lasia spinosa, Typha elephantina, Carex breviculmis, Zingiber
zerumbet, etc. are commonly found to cover the ground vegetation of this type of forest.
The annual flood submerges these forests by several centimetres every year leaving
the new alluvium and successive deposits of silts. These are first covered by the seedlings of
Tamarix, Salicornea which soon establish themselves in a dense form either in pure
formation or mixed with different grassy species. Moreover, in several places particularly in
Majuli and adjoining areas riverine areas composed of some hydrophilous herbs and sedges
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viz. Ranunculus scleratus, Anagallis arvensis, Cotula hemispherica, Ammannia baccifera,
Grangea maderaspatana, Gnaphalium luteoalbum, Polygonum chinense, Cyperus rotundus,
Fimbristylis dichotoma, Fimbristylis ovata, Scirpus articulates, etc.
2.5. Grassland and Savannahs:
This type of forest is one of the important components of the alluvial flood plains of
Brahmaputra valley as extensive areas of the state are dominated by grassland and
savannahs. This biome is primarily conspicuous in Kaziranga and Oranag national park,
Manas and Dibrusaikhowa biosphere reserves and wildlife sanctuaries viz. Sonai-Rupai,
Laokhoa, Pabitora, Barnadi, Bura Chapori etc. Generally the grassland vegetation of the
state can be differentiated into grasslands in recent alluvial deposits in low lying and char
areas annually inundated and flood water retained for a considerable period of time and
grasslands in old alluvium deposits of high land. Flood water scarcely reaches but the soil
remains moist only during rains where both pure grassland and savannah ecosystem occur
(Chowdhury, 2005).
Here tree species viz. Careya arborea, Bombax ceiba, Sterculia villosa, Lagerstroemia
parviflora, Dalbergia sissoo, Gmelina arbore, Premna bengalensis, etc. are scattered along
with grasses. The dominant grasses in wet alluvial grasslands are Apluda mutica, Phragmatis
karka, Sclerostachya fusca, Saccharum arundinaceum, S. procerum, S. ravennae, S.
spontataneum, etc. These species show luxuriant growth at the advent of rainy season,
often attain a height of over 5m and can withstand flood water. Other species of grasses
occur in these areas include Arundo donax, Arundinella pumila, Carex breviculmis, Eleusine
indica, Imperata cylindrica, Paspelidium flavidum, Paspalum conjugatum, etc.
2.6. Wetlands and swamps:
The mighty river Brahmaputra with its tributaries flows along the entire length of
Assam through a distance of 760 km. Extensive flood plains of Brahmaputra annually
inundated large patches of marshy depressions and swamps, perennial water reservoirs
locally called beels and community ponds. Almost all the national parks, biosphere reserves,
wildlife sanctuaries of the valley encompass vast patches of wetlands. The plants growing in
wetlands are usually termed as hydrophytes. Members of the families like Araceae,
Cyperaceae, Eriocaulaceae, Lemnaceae, Nymphaeaceae are common in these ecosystems.
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The growth and development of hydrophytes vary according to their habitats. Therefore the
hydrophytic vegetation of the valley is unique in terms of its floristic elements and will e
dealt separately elsewhere.
2.7. Degraded forest:
The impact and interference of both biotic and abiotic factors on the forest has
resulted in the formation of degraded forest in the state and the Brahmaputra valley is not
an exception to this. About 45% of the reserve forests are gradually depleted. The
commonly found plant species in these forests are Oroxylum indicum, Duabanga
grandiflora, Bombax ceiba, Saurauia nepaulensis, S. roxburghii, Croton roxburghii,
Macaranga denticulata, Eurya acuminata, Maesa indica, Clerodendrom viscosum, Callicarpa
arborea, Rubus rugosus, Eriobotrya benghalensis, Mikania micrantha, Ageratum conyzoides,
Saccharum spontaneum, Urena lobata, Solanum torvum, Leucas plukenetii, Zizyphus
mauritiana, Schizostachyum polymorphum, Lantana camara, Imperata cylindrica, etc.
CONSPECTUS OF THE FLORA
The flora of the state of Assam is rich both in terms of diversity and luxuriance.
stated earlier that lot of floristic studies have been
till date leading to the addition of the data on the floristics of the state. Moreover
protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,
Kaziranga NP, Oranag NP, Pabitora WLS, Laokhowa WLS along with other protected areas of
the Brahmaputra valley have already been explored floristically.
national parks of the valley is given in the
greatest river island of the Brahmaputra and that of Umananda has also been studied
(Appendix II).
Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley
As per conventional estimates the state flora comprise of 3017 species
1999). Chowdhury (2005) gave an account of the 4273 species of
taxa comprising of 1448 genera distributed in 272 families of vascu
These include fern allies, ferns gymnosperms and angiosperms.
Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state
by listing 3854 taxa (including infra
of which, 2752 taxa are dicotyledons, 1080 taxa are monoco
15995
580
882
0
100
200
300
400
500
600
700
800
900
1000
Nameri NP Rajib Gandhi (Orang) NP
Num
ber o
f the
taxo
n
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Chapter 3
CONSPECTUS OF THE FLORA OF BRAHMAPUTRA VALLEY
The flora of the state of Assam is rich both in terms of diversity and luxuriance.
stated earlier that lot of floristic studies have been made in the state right from 18
till date leading to the addition of the data on the floristics of the state. Moreover
protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,
itora WLS, Laokhowa WLS along with other protected areas of
the Brahmaputra valley have already been explored floristically. A list of flora of the 5
national parks of the valley is given in the Appendix I. The floristic composition of Majuli,
river island of the Brahmaputra and that of Umananda has also been studied
Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley
As per conventional estimates the state flora comprise of 3017 species
Chowdhury (2005) gave an account of the 4273 species of comprising infra
taxa comprising of 1448 genera distributed in 272 families of vascular plants of Assam.
fern allies, ferns gymnosperms and angiosperms. More recently Bar
Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state
3854 taxa (including infra-specific taxa) under 1394 genera and 236 families. Out
of which, 2752 taxa are dicotyledons, 1080 taxa are monocotyledons and 22 taxa are
95 111 108 115
322372
233
377450
591
471
560
Rajib Gandhi (Orang) NP
Manas NP & BR Dibru-Saikhowa NP & BR
Kaziranga NP
National Parks
The flora of the state of Assam is rich both in terms of diversity and luxuriance. As
made in the state right from 18th century
till date leading to the addition of the data on the floristics of the state. Moreover, the
protected areas situated along the riverine areas of the state particularly Dibrusaikhowa BR,
itora WLS, Laokhowa WLS along with other protected areas of
A list of flora of the 5
of Majuli, the
river island of the Brahmaputra and that of Umananda has also been studied
Fig. 1: Comparative account of the flora of the national parks of the Brahmaputra valley
As per conventional estimates the state flora comprise of 3017 species (Baishya
infra-specific
lar plants of Assam.
ently Barooah and
Ahmed (2014) compiled a detailed checklist of Angiosperms and Gymnosperms of the state
specific taxa) under 1394 genera and 236 families. Out
tyledons and 22 taxa are
Family
Genera
Species
gymnosperms (Appendix III). The flora of Assam represents
However, the figures are provisional as still many areas are underexplored and constant
changes are taking place in the flora due to human
ecological factors. As far as the habit is concerned, the percentage of tree in the flora is only
20% while the herbs occupy the highest 47% of the flora of the state.
Looking at the details of the floristic
observed that the floristic diversity of Brahmaputra valley is much rich than the Barak valley
as over 90% of the total flora of the state have been reported from Brahmaputra valley
According to Das (1942), Brahmaputra valley harbours more of Giant and diverse tree
species than in the Barak valley (Appendix IV
the two valleys are readily apparent with the localised elements not found any were else in
the state.
India82%
Fig. 2: Percentage of Angiosperms of Assam in the Indian flora
India5%
Fig. 3: Percentage of Angiosperms of Assam in the world
17
The flora of Assam represents 18% of the Indian flora.
However, the figures are provisional as still many areas are underexplored and constant
changes are taking place in the flora due to human interference, biotic pressure and other
As far as the habit is concerned, the percentage of tree in the flora is only
20% while the herbs occupy the highest 47% of the flora of the state.
Looking at the details of the floristic composition of the two valleys of the state
the floristic diversity of Brahmaputra valley is much rich than the Barak valley
0% of the total flora of the state have been reported from Brahmaputra valley
, Brahmaputra valley harbours more of Giant and diverse tree
Appendix IV).The difference in the floral compositions of
the two valleys are readily apparent with the localised elements not found any were else in
India82%
Assam18%
Fig. 2: Percentage of Angiosperms of Assam in the Indian flora
World94%
India5%
Assam1%
Fig. 3: Percentage of Angiosperms of Assam in the world
8% of the Indian flora.
However, the figures are provisional as still many areas are underexplored and constant
interference, biotic pressure and other
As far as the habit is concerned, the percentage of tree in the flora is only
composition of the two valleys of the state it is
the floristic diversity of Brahmaputra valley is much rich than the Barak valley
0% of the total flora of the state have been reported from Brahmaputra valley.
, Brahmaputra valley harbours more of Giant and diverse tree
).The difference in the floral compositions of
the two valleys are readily apparent with the localised elements not found any were else in
18
Chapter 4
SIGNIFICANCE OF THE FLORA
Vascular plants of the Brahmaputra valley show richness and luxuriance of the flora
due to occrrrence of over ninety percent species of the the flora of Assam. The luxuriant
vegetation and flora of the valley creates the treasure house multidimensional biotypes in
the area with prevalence of a number of endemic plant species and some important
primitive angiosperms. Apart from these, it is blessed with very high degree of
taxonomically and ecologically valued floral species. The richness of the composition is
reflected with more than 250 species of Orchids, 33 species of Bamboo, 12 species of Canes
and number of plants with medicinal properties. The forest cover of the state represents
35.28% area of the state with 17.68% of geographical area in Reserve Forest and 5% of
geographical area under protected area net work (Anonymous, 2011). It is noteworthy that
there are a larger numbers of rare, threatened and endangered species found in the state
outside the formal forest areas too.
Looking at the endemism in flowering plants, it is observed that the northeast region
has the largest concentration of endemic plants, as out of total 5725 endemic species found
in India, northeast region has a total of 1808 endemic species (Nayar, 1996). Although, the
comprehensive account of the endemic taxa of the state Assam is yet to be worked out, the
Botanical Survey of India listed 102 species of angiosperms belonging to 75 genera as
endemic taxa for the political boundary of Assam, of which majority i.e. 91 species
belonging to 68 genera are found in the Brahmapurta valley (Appendix V). The physio-
climatic conditions of the state particularly of the Brahmaputra valley are the place of active
speciation. Moreover, many endemic taxa are recorded from type locality and to pin point a
particular taxa as endemic to the valley may cause confusion as several part of northeast
region and also the country is under explored or unexplored.
The largest representation of endemic taxa from the state belongs to families
Poaceae, Lauraceae, Magnoliaceae, Orchidaceae and Piperaceae. Genus Piper has the
highest endemism in the valley with 6 species followed by other genera viz. Calamus,
Dioscorea and Magnolia are with 3 species each.
19
Several groups of flowering plants viz. Orchids, Legumes, Cucurbits, etc. exhibit
remarkable species diversity in the Brahmaputra valley. Apart from these, spectacular
species diversity has been observed in the genera like Dendrobium, Elaeocarpus, Piper,
Garcinia, Calamus and Dipterocarpus in the Brahmaputra valley. Families viz. Poaceae,
Orchidaceae, Fabaceae, Asteraceae, Araceae, Cucurbitaceae, Lauraceae, Arecaceae,
Zingiberaceae, etc. also contribute rich gene pool of the valley. The Brahmaputra valley has
made one of the greatest contributions to world agriculture by discovering the cultivation of
tea. The valley produces some of the finest and expensive teas in the world and has the
indigenous species Camellia sinensis var. assamica.
The area is also known for several plants of botanical curiosities. Various interesting
plants viz. species of Utricularia, Drosera, (all insectivorous plants), Sapria himalayana
(parasitic angiosperm reported from Sadiya probably extinct in the state), Balanophora
dioica, (parasitic angiosperm), etc. are available in the valley. Some of the phylogenetically
primitive families such as Magnoliaceae, Anonaceae, Schizandraceae, Menispermaceae,
Altingiaceae, Lardizabalaceae, etc. grow in the Brahmaputra valley and further eastwards
but do not occur in other parts of India (Appendix VI). The distribution pattern of these
primitive plants show that they are mostly localised and confined to the major forest types
i.e. evergreen and semi evergreen forests and also on the riparian belts. This array of
floristic richness has prompted many naturalists to describe Assam as the ‘Biological
Gateway’ of northeastern India. Armen L. Takhtajan (1969), the eminent plant taxonomist
and geographer observed ‘the cradle of flowering plants lies in between Assam and Fiji’.
The flora of the valley has distinct affinity with the nearby Nepal, Bhutan, Indo-
Burma, Sino-Himalayan, Malaysian and to a lesser extent with peninsular India. Species viz.
Albizzia procera, Antidesma acidum, Bischofia javanica, Bombax ceiba, Cassia fistula, Costus
speciosus, Duabanga grandiflora, Hedychium coccineum, Hodgsonia macrocarpa, Oroxylum
indicum, Tetremeles nudiflora are some examples of Indo-Burma and other southeast Asian
floristic elements found in the flora of Brahmaputra valley. Besides, the taxa like Camellia,
Eurya, Hoya, Maesa, Magnolia, Michelia, Hypericum, Viola, Sarauia etc. are some of the
examples of Sino-Himalayan affinity found in the flora of the valley. Some plants of African
and American flora are naturalized in the valley for eg. Pyrularia edulis of Santalaceae found
20
in western Assam and another solitary member in America are the best examples of
transpacific distribution.
Gymnospermic diversity in India accounts for 48 species (Singh & Mudgal, 1997) and
northeast region is represented by more than 28 species. Although the members of this
group of plant is less, they are equally important for providing timber, wood, pulp, resins,
tars, turpentine, etc. These gregarious plants mostly dominate the Himalayan landscape of
the state Arunachal Pradesh and Sikkim in northeast region. However, in Assam they are
poorly represented. In Brahmaputra valley they are restricted to Darrang, Dibrugarh,
Goalpara, Golaghat, Lakhimpur, Sibsagar and Sonitpur districts. As many as 5 species of
gymnosperm occur in the valley belonging to the families Cycadales, Coniferales and
Gnetales. Species viz. Cycas pectinata, Podocarpus nerifolia, Gnetum gnemon and G.
montanum are some of the common species of gymnosperm which grow naturally in the
valley.
In India the pteridophytic flora i.e. fern and fern allies are represented by over 1200
taxa under 204 genera distributed almost all the climatic zones of the country. The
northeastern region of India is regarded as the richest area of pteridophytic diversity that
supports more than 800 taxa of which 97 species are endemic. In Assam, fern allies and
ferns are the important component of biodiversity and Baishya (1999) and Chowdhury
(2005) estimated separately on the diversity of the pteridophytic flora of the state.
Borthakur et al. (2001) enumerated 87 genera and 221 species of fern and its allies from the
state. All those estimates suggest that the members of the family Polypodiaceae has the
highest representation followed by Thelypteridaceae, Pteridaceae and Athyriaceae in the
Brahmaputra valley. Besides the species of the genera Lygodium, Stenochlaena is very
widely distributed in the various forests of the valley. In the wetlands, generas viz. Azolla,
Ceratopteris and Salvinia are commonly found. Another fern of amphibian nature viz.
Marsilea is also commonly found in the valley. Other interesting species of ferns found in
the valley are Psilotum nudum, Huperzia phlegmaria, Osmunda regalis, Angiopteris evecta
etc. Likewise, the species representation of other cryptogamic group of plants such as Moss
(Musci), Liverworts (Hepaticae), Lichens, etc. are also remarkable in the Brahmaputra valley.
The northeastern region is also very rich in wild relatives of cultivated plants. The
region along with the rest part of the country is popularly known as Hindustani Centre of
21
origin of cultivated plants (Vavilov, 1926, 1951) and forms the richest reservoir of genetic
variability of many groups of crop plants. The state of Assam serves as a centre of origin of
economically important plants viz. Musa, Citrus, Mangifera, Zizyphus, Camellia sinensis var.
assamica. Singh and Varaprasad (2008), identified Brahmaputra valley as ‘Probable
Agricultural Heritage’ site due to unique and significant diversity in important crop plants.
According to Rao (1994), wild relatives of 189 economically important species such as Citrus,
Banana, Mango, Sugarcane, Pulses, cereals and other fruit plants are located in northeast
region including Assam. Hore (2001) estimated tentative number of crop diversities in some
major crops includes - Rice (9650+ races), Maize (15 races and 3 sub races), Banana (14
spp.), Citrus (17 spp., 52 varieties), Sugarcane and their wild relatives (15 spp.) and Bamboo
(60 spp.) in the northeast region.
22
Chapter 5
UTILITY OF THE FLORISTIC DIVERSITY
The rich floristic diversity of Brahmaputra valley has tremendous utilitarian value.
Plant resources available in the area starting from their timber yielding value can also be
used as medicines, as food, as source of essential oils, gums, for making paper and pulp,
dyes, resins, tannins, essential oils, fibres, etc. The valley harbours about 40 high prized
timber yielding plant species. There are over 1000 species of plant reported to have
medicinal properties available in the valley with commercial importance and are also used
by different communities for treating various ailments. Some of the highly valued medicinal
plants of Brahmaputra valley are Dioscorea bulbifera, Acorus calamus, Hydnocarpus kurzii,
Oroxylum indicum, Piper peepuloides, Rauvolfia serpentina, etc. Proper exploration of these
resources will lead to the discovery of novel drugs.
The state of Assam particularly Brahmaputra valley is famous for orchid diversity and
the orchid cut flowers are prized all over the world for their long lasting ornamental value
and are good source of revene generation. Many epiphytic and terrestrial orchids of
surpassing horticultural potential as well as the progenitors of the present day commercial
hybrids are available in the area. A list of the orchids of the State of Assam particularly of
Barhmaputra valley is presented in the Annexure I. Besides, several ornamental plants with
prospect for floriculture are found in the valley. Plant species viz. Agapetes, Arisaema,
Aster, Bauhinia, Begonia, Camellia, Cassia, Hedychium, Holmskioldia, Impatiens, Jasminum,
Mussaenda, Primula, Raphidophora, Tacca, etc. are potential floricultural plants.
The state is one of the important areas of northeast region as far as the production
of canes and bamboos are concerned. As many as 12 species of canes and 33 species of
bamboos are found in the Brahmaputra valley, which are of great importance in developing
forest based cottage industries in different parts of the valley. Apart from bamboos and
canes Thysanolaena maxima (broom stick), Imperata cylindrica (Thatch grass) are other
economically important grasses of the valley. A list of economically important plant species
are presented in Appendix VII.
Moreover, the cross cultural ethnobotany of the valley is also very rich as the area is
resided by diverse ethnic communities with wide range of uses of plants of different groups.
23
Saklani & Jain (1994) reported 332 plant species of Assam used as food, drinks, medicine
and also in cultural aspect. The statistics will go up if the information on ethnobotanical uses
of plants from new areas and different ethnic communities of the valley is incorporated. Use
of plants for a variety of purpose indicates the intimate relationships and dependence of
people of the area with the plant resources of their viscinity.
It may be mentioned here that majority of the total population of the area live in the
villages, interior areas nearby forests, and are enriched with plenty of traditional knowledge
system of resource utilization. About 40 species of various wild plants are marketed as food
and vegetables in local tribal and village markets of the valley. Patiri & Bora (2007) reported
350 species of wild edible plants of Assam used as green vegetables including root & root
like vegetables; some are also used as fruits and condiments along with seeds, Bark and
flowers.
The valley has a rich diversity of wild relatives of cultivated plants (Appendix VIII).
Wild crop diversity is considered as valuable biological assets as they are reservoir of various
genes of agronomic and economic importance needed for genetic improvement of crop
plants (Singh, 2010).
Like higher plants, the cryptogams are equally important as they are used in various
aspects such as food, medicine, dye, antibiotic, ornamental purpose, etc. Fronds of
pteridophytic plants viz. Diplazium esculentum, Drypetes elongata, etc. are eaten as
vegetables. Some species of Selaginella, Lycopodium, Adiantum, etc. are also used as
medicine. Similarly species of lichen such as Everniastrum cirrhatum is used as food,
Heterodermia diademata as antibiotic, Parmotrema tinctorum as dye. Different species of
edible mushroom such as Agaricus, Auricularia, Clavaria, Morchella, Pleurotus, etc. are
commonly available in the forests of the valley and are often sold in the local markets.
24
Chapter 6
HIGH PRIORITY TAXA
The rich plant diversity of the region in the recent years is witnessing serious threats
due to various abiotic and biotic factors. The gradual increase of human population,
developmental, oil extraction and other anthropogenic activities coupled with natural
calamities particularly seasonal flood and erosion of river banks, monocultural practice are
contributing directly or indirectly towards the loss of habitat of several plant species. As a
result several plant taxa become threatened and endangered in the flora of Assam and
Brahmaputra valley as well. Some species become rare due to over exploitation for
medicinal, ornamental and other industrial uses. According to an estimate of Botanical
Survey of India, about 700 plant species of northeast region fall under various threat
categories of which 43 species belong to Assam. Baishya (1999) compiled a list of 60 rare
and threatened plant taxa from Assam. Barooah and Ahmed (2014) categorised 871 taxa of
angiosperms and gymnosperms of the state under different conservational status. Among
these, 167 taxa are recorded to be endemic, 318 taxa are kept under critically endangered,
endangered and vulnerable and 386 taxa are identified as rare to the state.
The number will be much more if all the members of the family Orchidaceae are
included in the threat list. It may be mentioned that the entire family Orchidaceae is kept
under the Appendix II of the CITES. Orchid species viz. Vanda coerulea, Renanthera
imschootiana and all the species of Paphiopedilum found in the region as well as outside the
region are included under the Appendix I of CITES.
Sapria himalayana of family Rafflesiaceae which was reported from Sadiya long back
is at present presumed to be extinct in the state. IUCN-CAMP, 2003 categorised 18 plants of
the state in various threat categories. Some critically endangered species of the
Brahmaputra valley are region are Livistona jenkinsiana, Swertia chirayita, Smilax glabra,
etc. Plant viz. Aquilaria malaccensis, Brucea mollis, Cibotium barometz, Citrus macroptera
var. assamensis, Dendrobium nobile, Flickingeria fugax, Garcinia pedunculata, Homalomena
aromatica are endangered in the valley and vulnerable species include Elaeocarpus
sphaericus, Gynocardia odorata, Hydnocarpus kurzii, Mahonia napaulensis, Oroxylum
indicum, Piper peepuloides, Rauvolfia serpentina. A list of rare, threatened and endangered
25
plant taxa as prepared by Botanical Survey of India for the state of Assam in presented in
the Appendix IX (Nayar et al. 1987, 1988 & 1990; Baishya, 1999). The IUCN categories of
these taxa are also provided wherever available.
The present status in terms of exact location with GPS co-ordinates, population
density, regeneration capacity are required to be work out to formulate the conservation
strategy of these threatened and endangered plant taxa. Moreover, existence of certain
taxa is also need to be verified in view of recent nomenclatural changes. There is a chance of
wipe out many valuable plant species in a few decades if they are not given proper attention
for conservation.
26
Chapter 7
THREATS
The geographical isolation from rest part of the country has helped to protect the
biodiversity of northeast India from large-scale developmental activities. But the situation
has changed gradually and the biodiversity of the region is now confined to only a few
pockets. It was the British who first cleared the natural forest for tea plantation and
propagation of commercial species like teak (Tectona grandis), sal (Shorea robusta), hollock
(Terminalia myriocarpa), simul (Bombax ceiba), gamari (Gmelina arborea), etc. The forest of
the state has attracted the attention of the world in the middle of the 19th century with the
advent of railways in Bengal and is identified as the starting point of forest destruction in
the region. Shifting agricultural practice is another cause of forest destruction in the state of
Assam although it is prevalent only in the hill districts of Assam. However, in the extension
areas of Kaziranga National Park i.e. in Karbi Anglong hills this kind of agricultural practice
may lead to the destruction of the forest cover. To meet the increasing demand of the
growing population, the period of jhum cycle has been reduced to considerable rate,
affording no chance for natural regeneration and soil fertility. The rate of forest degradation
is also supported by the invasion of weeds. It has been observed that various species of
native and exotic weeds viz. species of Ageratum conyzoides, Argemone maxicana,
Chromolaena odorata, Lantana camara, Mimosa rubicaulis, Mikania micrantha, Parthenium
hysterophorus, etc. have completely dominated the forested land, degraded forests and the
agricultural landscapes of the region posing serious threat to all sorts of healthy growth of
plant species, forest regeneration and agricultural productivity as well. In Kaziranga national
park, proliferation of various weeds like Mikania, Mimosa and Eichhornia, causes ecological
degradation of the habitat and is a major problem confronting the Park authorities.
Although some serious eradication efforts particularly for Mimosa, removal of water
hyacinth etc. have been made in the recent past but still it is a threat to the wildlife habitat
of the park.
Natural calamities like earthquake, seasonal flood, etc. as well as soil erosion also
lead to the shrinkage of the forest cover in the region. Of late, the various developmental
activities like construction of mega dams, hydroelectric plants, roads, etc. also act as the key
27
factors of forest destruction in the state. The impacts (upstream and down stream) of large
river dams on ecosystem and environment as a whole are well established. Building of mega
dam on the mainstream of the Brahmaputra as well as on some of its major tributaries may
adversely affect the natural importance of some protected areas of the valley, for instance
Kaziranga and Manas national park. The survival of charismatic species like rhino, flagship
species like elephant and other herbivores in these critical ecosystems are determined by
natural connectivity of the forests with waters of the rivers that makes these ecosystems
capable to sustain certain types of grasses and other vegetation. Construction of large dams
may change the flood cycle and hydrological relationship of some critical ecosystem of the
state for example Kaziranga national park. The existence of different habitat types in the
park viz. grassland, wetland and also woodland is dependent on the annual sluicing of the
landscape by flood water. Moreover, the livelihood of the people living in the catchment
areas of the river would also be at stake.
Injudicious collection of various plant resources for medicinal, dye making and
ornamental purpose are very common that lead to the depletion of the rich bio-resources of
the state. Political and social unrest prevailed in the state for the last couple of decades are
also influencing adversely to the rich floristics of the state in general and the Brahmaputra
valley in particular.
As far as the diversity of cultivated crops is concerned, the replacement of local land
races by High Yielding Varieties (HYV) in cultivated fields has caused considerable loss in
diversities of crop and economically important plant in the region.
Along with the deforestation, degradation, encroachment and associated concerns
of logging, habitat fragmentation another important issue that need to be addressed for
Assam is the climate change. Because of its sensitive geo-ecological set-up, strategic
location with international boundary, presence of the Eastern Himalayan ranges,
transboundary river systems, inhabitation of ecosystem by people of different ethnic groups
and inherent socio-economic differences, the state is expected to be highly prone to
consequences to climate change.
28
Forest ecosystems in particular are among the natural systems that will globally be
severely affected by climate change (Pérez-García et al., 2002; Walther et al., 2002). This is
also true for the forests of Assam and its adjoining northeastern states. At the ecosystem
level, due to increase in atmospheric carbon dioxide and resultant temperature increases
and there will be changes in rainfall regimes. This may result in increase in biomass
production, alteration in forest structure and species composition and competitiveness,
(Meer et al. 2001). At the community level, changes in floral phenology will likely to impact
adversely the critical process of pollination and seed dispersal.
Climate change thus expected to impose a variety of stress on sustainable livelihood
of the poor inhabitants of the state through stresses on ecosystem function. The major
concerns are erratic & irregular rainfall patterns, longer dry spells, and implications on
agriculture calendar, productivity, new pests; food security; health and disasters like flash
floods. It is presumed that there would be a change in distribution, abundance of species,
more particularly wild, endemic species, crop plants, pests and vectors. Due to change in
habitat condition, displacement both human and other wilderness would take place. Apart
from these, the food security, mitigation of hazards and addressing the epidemics like
malaria, encephalitis etc. are other issues of major concerns for the state (Bujarbarua &
Baruah, 2009). The marginalised people of the state who are dependent on the forests for
basic livelihood needs such as fuelwood, bamboo, fodder, timber and Non Timber Forest
Products including medicinal plants may face adverse consequences due to climate change.
It worth to mention that, besides, traditional resource use, forests also provide germplasm
(Anonymous, 2011).
Thus the impacts of climate change on forest may lead to decrease in water
regulation and forest ecosystem services that may lead to increase social vulnerability. The
growing human population and livestock pressure may gradually widen the gap between
demand and supply of natural resources. These impacts will cut across multiple dimensions
of day to day life affecting not just the environment but the communities as well. Under
such circumstances, there is possibility of conflicts over reduced natural resources and may
cause strained social relations taking toll on to the cultural and spiritual services provided by
ecosystems (Bujarbarua & Barua, 2009).
29
Chapter 8
PROBLEMS OF FOREST MANAGEMENT IN THE BRAHMAPUTRA VALLEY
Environmental problems in the state of Assam have been influenced partly by the
increasing population, survival needs of the poor and the economic greed of the commercial
interests. They are also aggravated by prevalent economic disparities and unemployment,
which are deeply embedded in unsustainable patterns of production and consumption; ill
informed policies and programs; and inappropriate developing strategies. As far as the
forest resources of the Brahmaputra valley is concerned, gap in scientific knowledge,
increasing demands, lack of value addition are the main causes for which the vast potential
is yet to be tapped properly and in some cases over exploited.
Gap in scientific knowledge on various forest resources and products is a major
problem for management of resources in the state. Although considerable amounts of
revenue have been collected from forest products where local people are also directly or
indirectly involved in gathering and in some cases marketing as well, but they have hardly
any knowledge on the silvicultural management of various minor forest products. Except for
some well known commercial species, the information on distribution of various forest
products, their density, regeneration status, yield estimate and harvesting levels are lacking.
There is need to formulate sound management plan that addresses the knowledge about
the life cycle pattern of the species, productivity and yield estimation techniques.
As a result of the increasing demands of various forest resources, there is a danger of
fall in harvest in considerable rate. For example, Aquilaria malaccensis (Agar) is harvested
only after fungal attack. But due to its high commercial value, plants without fungal
infection are also harvested leading to the tremendous loss of natural population. Same
with the case of Oroxylum indicum- a high valued anticancer medicinal plant. Indiscriminate
collection of other medicinal plant species has caused wide spread loss to the natural
population of these species. IUCN-CAMP (2003) has already categorised 12 species of
medicinal plants of the state under various threat categories.
30
Valuation of biological resources is the most important aspect of its conservation,
sustainable use and management. Proper valuation of rich and vast bio-resources of the
state is yet to be done in terms of consumptive, non consumptive and productive use value.
Moreover, middle men are much benefited rather than the actual collectors as far as the
trade of forest products are concerned because of their inability to cope with exploitation
from the middle men. Poor knowledge about processing, market fluctuations cause post
harvest loss leading to insufficient returns of the products and ultimately causing over
exploitation.
Monitoring and maintaining of the complex ecosystem is important aspect of bio-
resource management. Technical aspects include choice between different methods and
techniques and development of appropriate harvesting and processing technologies. There
is also social aspect of resource management that deal with people, cultures, belief systems,
attitudes and behaviour, ethics, aspirations and social values. As far as the state of Assam is
concerned, all these aspects should be taken into consideration prior to the formulation of
management strategies. Finally, exercise of administrative power in another important
aspect to hold control over users of resources and decision-making.
In the perspective of the state of Assam, proper assessment of various forest
ecosystems and resources, their potential in supporting life and livelihood are the foremost
requirement. Moreover, there is little knowledge about the status of the forest resources,
products that are extracted commercially from the valley, their distribution, rate of growth,
threats. The sustainable management of these resources requires the collection of accurate
information and a programme of regular monitoring. Information on density and
distribution of the economically important species within the forest, population structure,
productivity, regeneration capacity and ecological impact of harvest are prerequisite for the
planning, design of management strategies and running enterprise based on raw materials
collected from the forest.
The concept of sustainable forest management can also be tested in the state as it
encompasses the wider issues and values. IIFM 2000 defined Sustainable Forest
Management (SFM) as ‘a management approach to obtain full range of forest values
31
ensuring that the ecological, economic and social needs of the present and future
generations can be met from the forest on a continuous basis’. Forest manage in this aspect
would not only provide timber on a sustainable basis but would also provide various forest
products and other services to the community living in and around it. It will also help to
preserve genetic resources and biodiversity and at the same time environmental balance
will also be maintained.
As far as the management of the wildlife habitats are concerned, lesson may be
learnt from the Kaziranga National Park. The Habitat management in Kaziranga is aimed
basically at restoration of grasslands - the main habitat of Rhino and most of the habivores
and is achieved through controlled burning. De-siltation of water-bodies and channels,
construction of temporary dam for water retention and control & eradication of weeds are
other measures adopted for habitat management of the park.
Maintanance of seral stage of grassland is the important aspect of the habitat
management in Kaziranga national park thereby preventing invasion of tree species. Thus
annual burning of grassland is practiced to discourage the growth of tree sapling. This not
only helps in enhancing the nutritional value of coarse grasses by facilitating growth of new
shoots but also attracts the herbivores. Moreover, siltation of water bodies due to flood
inside the park is a perennial problem leading to the shrinkage of water bodies. To address
this issue desiltation drives are carried out inside the park annually and are submitted useful
to maintain the water bodies which are integral part of the national park. Migratory birds
are important components of the biodiversity of Kaziranga. Therefore to retain the water in
the water bodies for attracting various migratory avifauna bunds are constructed. All these
habitat management practices are integral part of the conservation success of Kaziranga
national park. It is thus important that this success story be replicated in the other protected
areas of the state too to conserve the pristine biodiversity.
32
Chapter 9
DISCUSSION
The Brahmaputra valley is blessed with very high degree of endemic, taxonomically
and ecologically high valued plant species. The richness of the composition is reflected with
over 3000 species of flowering plants, over 250 species of Orchids, 33 species of Bamboo, 12
species of Canes and plants of other economic uses. The forest cover of the state represents
35.30% area of the state with 17.68% of geographical area in Reserve Forest and 5% of
geographical area under protected area net work. It is noteworthy that there are a larger
numbers of rare, threatened and endangered species found in the state outside the formal
forest areas too.
Recent years are witnessing considerable developments and the overwhelming
demand for forest based raw materials, especially bamboo, cane and natural health
products, which are renewable natural resources. Moreover, there is growing market
demand globally for these products. However, majority of these species in wild are under
severe threat, many are on the verge of extinction due to imprudent resource use and
management practices. Therefore it is imperative that multi-dimensional action (social,
ecological, economical, institutional) needs to be urgently taken for the conservation of
these vital resources. Management plan should be in such a way that livelihood
improvement and biodiversity conservation are in balanced state in order to reduce the
poverty and underdevelopment of the state. There is a need of sustainable management of
the important forest resources of the valley that would also contribute to the food security,
poverty alleviation, economical development, and sustainable land use, in the wider context
of sustainable development. Good forest management secures the survival of forest
ecosystems and enhances their environmental, socio cultural and economic functions. It can
both maximize forests’ contribution to climate change mitigation and help forests and
forest-dependent people adapt to new conditions caused by climate change (ASTEC, 2011).
As far as the state of Assam is concerned there is a need of policy based initiatives to
protect and conserve the pristine biodiversity of the state. It may be mentioned that the
state has lost several hectares of forest cover in recent years. There is large scale unabated
33
encroachment in the reserved forests even in the protected areas by the new settlers,
people displaced by floods and ethnic clashes in the state particularly the Brahmaputra
valley, immigrants and excessive dependence of the people in the rural areas on the forests
leading to deforestation. According to a report of forest department, 3,555 sq. km. of the
forest land is under encroachment (Anonymous, 2012). The encroachment in reserved
forests is a major concern in the management and conservation of forests of the state. The
forest survey data reveal that loss of forest cover in the State has been increasing over the
years. One of the general factors underlying these trends is land use land cover change, the
dynamics of which vary greatly across the state. The state has experienced rapid
urbanization, infrastructure development and the agricultural intensification with resulting
large scale habitat loss and degradation. Special strategy may be formulated for recovering
encroached areas.
Incorporation of some incentive mechanisms or benefit sharing mechanisms in the
community conserved areas for instance Mulai Kathoni (Jorhat) and protection of valuable
species outside the forest would be an encouraging steps towards conservation and
management of biodiversity. Important carbon stocks in many forests around the world
have been maintained and enhanced with the help of the local communities’ ranges from
conservation to reforestation.
Payments for ecosystem services may be useful in this regard for preserving,
acknowledging and rewarding good community forest management practices. Active
participation of communities in all aspects of forest management, taking into account
people’s needs, aspirations, rights, skills and knowledge, will contribute to the efficiency,
sustainability and equity of forest-based measures to tackle the degradation and threats of
climate change as well.
For reclamation of degraded forest lands and riparian sites, plantation and
ecorestoration programme may be initiated with prioritize species in relation to ecoregion/
agro-climatic zones. In riparian sites plantation of bamboo and various species of grass can
be initiated to check erosion. Eco-sensitive zones in the valley should be demarcated and
regulations may be imposed on developmental projects like mega dams, industrial activities,
34
quarrying and mining in such areas are other important measures of conservation may be
initiated.
More areas should be incorporated under protected area network. Strengthening of
the ongoing programme/project of forestry sectors, viz. Joint Forest Management, Project
Tiger, Project Elephant, Project Rhino, Eco-development programme, National aforestation
programme, etc. is important and these should be integrated with watersheds, wetlands
and also grass lands for formulating effective management planes. Special initiatives need to
be taken for protection of the areas outside the protected areas or reserve forests with rich
flora and fauna. The natural corridors of the wildlife in the valley disrupted due to change in
the land use and land cover, industrialization and other developmental activities should be
protected and restored.
Updation of the database on floristic diversity in terms of species, ecosystems &
genetic traits with reference to status, pressures and also in regard to changing climate are
other issues of resource management. Besides, pest-resistant or drought-tolerant varieties;
genotypes of species expected to be adapted to new climate conditions are also to be
screened out. Documentation ethno-cultural interlink is also important to safe guard IPR of
the communities.
The state of Assam should try for lobbying at regional, national and international
level against the large dams coming up on the Siang, Dibang, Lohit, Subansiri and even in the
Brahmaputra river. Exchange of surface, sub-surface and ground water flow is important for
maintaining the annual flood cycle and hydrological relationship of some important wildlife
areas of the valley. Probable changes in water flow due to construction of large dams may
significantly affect the supply of water, nutrient and silt which are vital for sustenance of the
forest and various ecosystem types.
The threat to biodiversity due to invasive species alien species is considered second
only to the habitat destruction. Invasive species cause loss of biodiversity including species
extinction. The humid climate of the state is congenial for spread various invasive and alien
species like Lantana camara, Mikania micrantha, Chromolaena odorata, etc. Special
35
measures to be taken for control of the alien /invasive plant species as several interacting
factors contribute to successful invasion of these species. There is a need to increase public
awareness of the threat of invasive plants to natural and man made ecosystems. Increased
awareness wil help prevent the translocation of invasive species in new areas.
As far as the conservation efforts are concerned, research inputs are important.
Therefore comprehensive studies on the floristics, phenological responses of wild flora in
different ecosystems/habitat, identification of plant species with high carbon sequestration
potentials need to be initiated. Identification of keystone species for different eco-zones
with perspective of developing strategies for eco-restoration, research on the sensitivity of
the endemic taxa to probable change including the possible impact on restricted range are
other areas of research. Apart from these some long term study on the changes on the life
cycle, physiology, reproductive biology some economically important plant species, also
with reference to climate change may be initiated. Similarly, problems of invasive species,
natural adaptation mechanism of species and the degree of resilience of their habitats are
also required to be addressed. Intensity of diseases of wild flora due to changing climatic
conditions is another issue need to be addressed as an adaptation measures to climate
change in the state of Assam. Besides, the vulnerability of major forest types and associated
fauna found in the state to climate change in PAs, grassland, riparian forests (prone to
erosion & flooding) and patches of the rain forests in upper Assam and also areas outside
the PAs need to be initiated to assess the impacts of climate change and possible adaptation
interventions.
All these initiatives are fruitless without involvement of the local communities.
Therefore, community training and capacity building are necessary prerequisites to local
biodiversity conservation programme and also for income generation. It is imperative that
the local communities should be made aware of the benefits of nature conservation. They
should also be imparted with technical, financial, managerial, marketing and training
support so that they will have a new economic incentive to conserve the resource base of
their raw material.
36
Various government institutions like North East Development Finance Corporation
Ltd. (NEDFI), North East Council (NEC) and Department of development of North East Region
(DONER) have already started encouraging to tap the vast bio-resource of the northeast
region in general and Assam in particular involving both local citizen as well as state
governments in a sustainable way to boast the economy and to provide livelihood to the
entire population of northeast India. Citizens are provided with technical, financial,
managerial, marketing and training support, so that they have a new economic incentive to
conserve the resource base. There must be co-ordination between government
developmental policies and biodiversity conservation strategies so that the critical balance
between the ideology of conservation and the necessity of development are maintained
involving local communities as the principal stakeholders of bio-resources.
There is a need to reassess the challenges and opportunities of sustainably managing
the bio-resource of the state. The strategies should be formulated in the context of all the
imperatives of biodiversity conservation, livelihood improvements and unsustainable
commercial utilization. The rich floristic diversity with a large number of endemic plants of
state of Assam in general and Brahmaputra valley in particular not only constitutes the
‘green gold’ of the present century but also of the future. These rich genetic resources of
the region also hold promises to yield organisms. A rational, scientific and judicious
utilization of the bio-resources of the region will help us in the long run in improving the
welfare of the humanity; at the same time will also facilitate to conserve this pristine glory
for the posterity.
37
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43
Appendix I: Floristic diversity of the national parks of Assam
Nameri NP
Begum,
2010
Rajib Gandhi (Orang) NP
Nath & Choudhury,
1994
Manas NP & BR
Hajra &
Baishya, 2002
Dibru-Saikhowa NP & BR
Baishya & Bora,
2002
Kaziranga NP
Hajra & Jain, 1996
District Sonitpur Darrang & Sonitpur
Kokrajhar, Chirang, Baska
& Udalguri
Tinsukia & Dibrugarh
Golaghat, Nagaon & Sonitpur
Area 200 sq. km.
78.81 sq. km. 500 sq. km. 340 sq. km. 430 sq. km
Family 159 95 111 108 115
Genera 580 322 372 233 377
Species 882 450 591 471 560
44
Appendix II: Floristic diversity of the Islands of Brahmaputra river.
Plant Group Flora of Majuli Island (M. Islam, 1990)
Flora of Umananda Island (P. Bujarbarua, 2015)
Families 139 54
Genera 505 117
Species (Angiosperms) 692 123
45
Appendix III: Floristic diversity of Assam worked out by different workers.
Plant Group Baishya (1999) Chowdhury (2005) Barooah & Ahmed (2014)
Family Genera Species Family Genera Species Family Genera Species
Fern & Fern allies - - 297 32 97 355 - - -
Gymnosperm 4 4 7 8 13 23 7 14 22
Angiosperm
(Dicotyledons)
170 824 2251 190 1006 2823 189 1011 2752
Angiosperm
(Monocotyledons)
37 287 759 42 332 1072 40 368 1080
46
Appendix IV: Comparisons of Evergreen species distributed in
Brahmaputra and Barak Valley (after Das 1942)
Brahmaputra valley Barak valley
Magnoliaceae
Magnolia griffithii Absent
M. hookeri Absent
M. cavena Absent
M. pealina Absent
M. pterocarpa Absent
M. insignis Absent
M. hodgsoni M. rabaniana
Pachylarnax pleiocarpa Absent
Kadsura roxburghiana Absent
Annonaceae
Polyalthia simiarum Absent
Absent Cyathocalyx malabaricus
Flcourtiaceae
Hydnocarpus kurzii Absent
Clusiaceae
Garcinia affinis Absent
Absent Mammea suriga
Maesa assamica Maesa floribunda
Theaceae
Adiandra griffithii Absent
Camellia caudate Absent
Dipteroarpaceae
Dipterocarpus retusus Dipterocarpus turbinatus
D. mannii Absent
Shorea assamica Absent
Hopea shingkeng Absent
Fabaceae
47
Dalbergia assamica D. reniformis
Derris ferruginea Absent
Absent Maniltoa polyandra
Hamamelidaceae
Altingia excels Absent
Combretaceae
Absent Anogeissus acumata
Myrtaceae
Eugenia Formosa Absent
Lythraceae
Crypteronia paniculata Absent
Sapotaceae
Palaquium obovatum P. polyanthum
Ebenaceae
Absent Maba cacharensis
Apocynaceae
Chonemorpha griffithii Absent
Asclepiadaceae
Cryptolepis buchanani Absent
Lauraceae
Beilschmiedia roxburghiana Absent
B. assamica Absent
B. pseudomicrocarpa Absent
Absent Endiandra firma
Absent Cinnamomum cacharensis
Alseodaphne petiolaris Alseodaphne owdenii
Absent Alseodaphne andersonii
Persea bombycina Absent
P. globularia Absent
Phoebe goalparensis Absent
P. cooperiana Absent
Euphorbiaceae
48
Aporusa wallichii Absent
Absent Drypetes eglandulosa
Fagaceae
Lithocarpus elegans Absent
Podocarpaceae
Podocarpus nerifolius Absent
Absent P. wallichianus
Gnetaceae
Gnetum gnemon Absent
49
Appendix V: Endemic plant taxa of Assam
Sl. No. Species Family
1 Acacia diadenia Mimosoideae
2 Acacia pennata ssp. Herrii Mimosoideae
3 Adhatoda cymosa Acanthacecae
4 Agapetes kanjilali Vacciniaceae
5 Agapetes variegata var. bhareliana Vacciniaceae
6 Allophyllus chartaceous Sapindaceae
7 Ardisia pardalina Myrsinaceae
8 Artabotrys cubitti Annonaceae
9 Bambusa cacharensis Poaceae
10 Bambusa mastersii Poaceae
11 Begonia tessaricarpa Begoniaceae
12 Beilschmiedia gammieana Lauraceae
13 Beilschmiedia pseudomicropora Lauraceae
14 Bousigonia angustifolia Lauraceae
15 Camellia sinensis var. assamica Theaceae
16 Calamus floribundus var. drepauperatus (Cachar & N.C. Hills) Arecaceae
17 Calamus kingianus (Cachar & N.C. Hills) Arecaceae
18 Calamus nambariensis (Cachar & N.C. Hills) Arecaceae
19 Celastrus paniculata var. venulosoides Celastraceae
20 Chonemorpha assamensis Apocynaceae
21 Chrysoglossum assamicus Orchidaceae
22 Cinnamomum cacharensis (Cachar & N.C. Hills) Lauraceae
23 Citrus assamensis Rutaceae
24 Cymbopogon jwaracus var. asamensis Poaceae
25 Dalbergia rimosa var. griffithii Papilionoideae
26 Dendrocalamus patellaris Poaceae
27 Dendrobium assamicum Orchidaceae
28 Dendrobium aurantiacum Orchidaceae
29 Derris cuneifolia var. cuneifolia forma assamica Papilionoideae
50
30 Dinochloa indica Poaceae
31 Dioscorea cumingii var. inacquefolia Dioscoreaceae
32 Dioscorea pentaphylla var. communis Dioscoreaceae
33 Dioscorea pentaphylla var. kussok Dioscoreaceae
34 Diospyros cacharensis (Cachar & N.C. Hills) Ebenaceae
35 Diospyros kika Ebenaceae
36 Dipterocapus manii Dipterocarpaceae
37 Dischidia albiflora Asclepiadaceae
38 Drypetes assamica Euphorbiaceae
39 Ecdysanthera lakhimpurensis Apocynaceae
40 Eria calmifolia Orchidaceae
41 Eulophia santapaui Orchidaceae
42 Euonymous assamicus Celestraceae
43 Euonymous vagans ssp. Macrophyllus Celestraceae
44 Fimbristylis circumciliata Cyperaceae
45 Fissistigma santapaui Annonaceae
46 Flacourtia helferi Flacoutiaceae
47 Garcinia keeniana (Cachar & N.C. Hills) Clusiaceae
48 Garcinia lanceafolia var. oxyphylla Clusiaceae
49 Gigantochloa macrostachya Poaceae
50 Glochidion assamicum Euphorbiaceae
51 Glycosmis singuliflora Rutaceae
52 Heritiera dubia Sterculiaceae
53 Homalium ceylanicum var. debbermani Flacoutiaceae
54 Hymenachne assamica Poaceae
55 Hypericum assamicum Hypericaceae
56 Illigera gammiei Hernandiaceae
57 Ixora goalparensis Rubiaceae
58 Justicia craibii Acanthaceae
59 Litsaea assamica Lauraceae
60 Maba cacharensis (Cachar & N.C. Hills) Ebenaceae
61 Maesa kurzii Myrsinaceae
51
62 Maesa maxima Myrsinaceae
63 Magnolia baillonii Magnoliaceae
64 Magnolia caveana Magnoliaceae
65 Magnolia gustavi Magnoliaceae
66 Mesua assamica Clusiaceae
67 Michelia manii Magnoliaceae
68 Michelia montana Magnoliaceae
69 Mussaenda intuspilosa Rubiaceae
70 Myristica clarkeana Myristicaceae
71 Pachylarnax pleiocarpa Magnoliaceae
72 Pandanus assamensis Pandanaceae
73 Parakaempfera synantha Zinziberaceae
74 Paspalum longifolium var. lorirhachis Poaceae
75 Pavetta assamica Rubiaceae
76 Persea dubia Lauraceae
77 Persea globularia Lauraceae
78 Phoebe cooperiana Lauraceae
79 Phoebe goalparensis var. marliniana Lauraceae
80 Phoebe goalparensis var. boriana Lauraceae
81 Phyllostachys assamica (Cachar & N.C. Hills) Poaceae
82 Physurus hirsutus Orchidaceae
83 Piper clarkei Piperaceae
84 Piper crassistipes Piperaceae
85 Piper gullatlyi Piperaceae
86 Piper gammei Piperaceae
87 Piper jenkinsii Piperaceae
88 Piper listeri Piperaceae
89 Poa wardiana Poaceae
90 Polygonum sarbhanganicum Polygonaceae
91 Rotboellia goalparensis Poaceae
92 Salacia jenkinsii Celestraceae
93 Schizostachyum dulooa (Cachar & N.C. Hills) Poaceae
52
94 Schizostachyum griffithii (Cachar & N.C. Hills) Poaceae
95 Schizostachyum pergracile (Cachar & N.C. Hills) Poaceae
96 Sclerostachya milroyi Poaceae
97 Syzygium assamicum Myrtaceae
98 Stztguyn cyanophyllum Myrtaceae
99 Thamnocalamus prainii Poaceae
100 Trachelospermum assamense Apocynaceae
101 Typhonium listeri Araceae
102 Uvaria hamiltonii var. kurzii Anonaceae
53
Appendix VI: List of primitive families and genera and representative species in the Brahmaputra valley
Family Genera No. of Species in Assam
Magnoliaceae
Magnolia 9
Michelia 8
Pachylarnax 1
Annonaceae
Alphonsea 1
Annona 3
Artabotrys 2
Desmos 4
Fissistigma 3
Friesodielsia 1
Goniothalamus 1
Miliusa 2
Mitrephora 1
Orophea 1
Poyalthia 4
Trivalvaria 1
Uvaria 4
Schizandraceae Kadsura 1
Menispermaceae Aspidocarya 1
Pycnarrhena 1
Lardizabalaceae Parvatia 3
Hamamelidaceae Altingia 1
Chloranthaceae Chloranthus 1
Myristicaceae
Horsfieldia 2
Knema 2
Myristica 1
Lauraceae
Actinodaphne 5
Beilschmiedia 5
Cinnamomum 5
54
Cryptocaria 2
Dehaasia 1
Endiandra 1
Lindera 5
Litsea 19
Machilus 2
Neocinnamomum 1
Persea 5
Phoebe 5
Saururaceae Houttuynia 1
Myricaceae Myrica 1
Betulaceae Betula 1
Gnetaceae Gnetum 3
Podocarpaceae Podocarpus 1
Cycadaceae Cycas 1
55
Appendix VII: Economically important plants of Brahmaputra valley
Category Name of the plant species
Timber yielding plants Albizia lebbek, A. odoratissima, Altingia excelsa, Artocarpus
chama, Chukrassia tabularis, Duabanga grandiflora, Dipterocarpus
retusus, Mesua ferrea, Michelia champaca, Species of Magnolia,
Talauma hodgsonii, Palaquium polyanthum, Schima wallichii,
Phoebe goalparensis, Shorea assamica, S. robusta, Terminalia
myriocarpa, Lagrestroemia reginae.
Paper and pulp: Besides Bamboo, plants viz. Garuga pinnata, Bombax ceiba,
Helicteres spp., Kydia calycina, etc. forms the raw material for
paper industries.
Gums and resins Canarium strictum is the important resin yielding plant of Assam.
Essential oils Brahmaputra valley is rich habitat for Cymbopogon flexuosus,
yielding Citronella oil. Other oil yielding species are Hydnocarpus
kurzii, Gynocardia odorata, Mesua ferrea, Homalomena
aromatica, Pogostemon cablin, etc. Aquillaria malaccensis is the
high valued oil yielding plant found in the state of Assam
particularly in the Brahmaputra valley.
Fibre yielding plant The important fibre yielding plant found in the area are Sterculia
villosa, Bombax ceiba, Corchorus spp., Boehmeria nivea, Butea
monosperma, Bauhinia spp., Grewia spp., Firmiana colorata, and
the species of Hibiscus.
Bamboos and canes: Some important bamboo species are - Bambusa balcooa, B.
pallida, B. cacharensis, B. tulda, Dendrocalamus hamiltonii, D.
strictus, D. giganteus, Melocanna bambusoides, M. baccifera, etc.
Cane species include Calamus flagellum, C. floribundus, C.
latifolius, C. tenuis, etc.
Medicinal plants: Adhatoda vasica, Centella asiatica, Clerodendron colebrookianum,
Costus speciosus, Zingiber gerumbet, Hollarhoena antidysenterica,
Paederia foetida, Phyllanthus emblica, Eclipta alba, Asparagus
racemosus, Terminalia bellirica, T. chebula, etc.
56
Plants with horticultural
importance
Orchids viz. Arundina bambusifolia, Rhynchostylis retusa,
Papilionanthe teres, Cymbidium aloifolium, Dendrobium spp., etc.
along with Allamanda cathartica, Bauhinia purpurea, B. variegate,
Canna indica, Cassia fistula, Celosis argentia, Cestrum nocturnum,
Clerodendrum spp., Hedychium spp., Holmskioldia sanguine, Ixora
acuminata, Saraca indica, Mussaenda spp. are some of the
important plant species with horticultural and floricultural
importance.
Dye Bixa orenella, Rubia cordifolia, Talauma hogdsonii, etc.
Cereals, pseudo-cereals
and millets
Eleusine coracana, Setaria italic, Zea mays, Oryza sativa, etc.
Grain legumes and
oilseeds
Vigna mungo, V. vexillata, V. umbellate, Cicer arietinum, Lens
culinaris, Linum usitatissimum, Brassica juncea, B. rapa, Cajanas
cajan, Sessamum indicum, etc.
Tubers Beta vulgaris, Amorphophallus bulbifer, Ipomoea batatus,
Colocasia esculenta, Dioscorea alata, D. bulbifera, D. hispida, etc.
Spices Pimpinella anisum, Ammomum aromaticum, Nigella sativa, Piper
nigrum, Piper peepuloides, Elettaria cardamomum, Cinnamomum
tamala, Syzygium aromaticum, Cinnamomum zeylanicum, Alpinia
malaccensis, Zingiber officinale, Z. zerumbet, Cymbopogon
jawarancusa var. assamensis, Curcuma amada, Curcuma longa,
etc.
Minor fruits Musa spp., Dillenia indica, Flacourtia jangomas, Baccaurea
ramiflora, Garcinia pedunculata, G. sopsopia, G. stipulata, G.
xanthochymus, Artocarpus lakoocha, Terminalia chebula,
Holboellia latifolia, etc.
57
Appendix VIII: Wild relatives of cultivated plants found in the Brahmaputra valley
Sl. No Name of the Plant Family
1 Artocarpus chama Moraceae
2 Brassica trilocularis Brassicaceae
3 Camellia kissi Theaceae
4 Cinamomum bejolghota Lauraceae
5 Cinnamonum glanduliferum Lauraceae
6 Cinnamomum pauciflorum Lauraceae
7 Citrus assamensis Rutaceae
8 Citrus indica Rutaceae
9 Coffea bengalensis Rubiaceae
10 Coffea fragrans Rubiaceae
11 Colocasia fallax Araceae
12 Colocasia mannii Araceae
13 Cucumis hystrix Cucurbitaceae
14 Cucumis trigonus Cucurbitaceae
15 Curcuma amada Zingiberaceae
16 Curcuma aromatic Zingiberaceae
17 Dioscorea hamiltonii Dioscoreaceae
18 Dioscorea sinensis var. assamica Dioscoreaceae
19 Echinochloa crusgalli Poaceae
20 Elaeocarpus floribundus Elaeocarpaceae
21 Eleusine indica Poaceae
22 Erianthus filifolius Poaceae
23 Erianthus ravennae Poaceae
24 Euonymus assamicus Celastraceae
25 Euonymus vagans Celastraceae
26 Garcinia keeniana Clussiaceae
27 Garcinia lanceaefolia Clussiaceae
28 Luffa graveolens Cucurbitaceae
29 Mangifera sylvatica Anacardaceae
30 Miscanthus nudipes Poaceae
58
31 Miscanthus wardii Poaceae
32 Momordica macrophylla Cucurbitaceae
33 Musa assamica Musaceae
34 Musa acuminate Musaceae
35 Musa velutina Musaceae
36 Narenga fallax Poaceae
37 Oryza rufipogn Poaceae
38 Piper peepuloides Piperaceae
39 Polytoca wallichiana Poaceae
40 Prunus cerasioides Rosaceae
41 Prunus nepalense Rosaceae
42 Rubus moluccanus Rosaceae
43 Saccrahum longisetosum Poaceae
44 Saccharum wardii Poaceae
45 Solanum kurzii Solanaceae
46 Syzygium assamicum Myrtaceae
47 Trichosanthes bracteata Cucurbitaceae
48 Vigna clarkei Fabaceae
49 Zingiber spectabilis Zingiberaceae
59
Appendix IX: Rare, Threatened and Endangered Plant Taxa of Assam (Both Brahmaputra and Barak valley, Source: Baishya, 2009)
Sl.
No. Species Family Status
1 Acalypha australis Euphorbiaceae Rare
2 Acanthephippium silhetense Orchidaceae VulnerableIUCN
3 Acranthera tomentosa Rubiaceae Vulnerable, Endemic, Not EvaluatedIUCN
4 Adinandra griffithii Theaeceae EndangeredIUCN
5 Albertisia mesistophylla Menispermaceae Extinct, Not EvaluatedIUCN
6 Anoectochilus sikkimensis Orchidaceae Critically EndangeredIUCN
7 Apostasia nuda Orchidaceae EndangeredIUCN
8 Begonia tessaricarpa Begoniaceae Extinct, Not EvaluatedIUCN
9 Beilschmiedia pseudomicropora Lauraceae Endemic, Not EvaluatedIUCN
10 Brassiopsis polycantha Araliaceae Rare
11 Bulbophyllum mishmeense Orchidaceae Rare, Endemic Sunipia cirrhata
12 Bulbophyllum virens Orchidaceae Rare, Endemic Sunipia virens
13 Calanthe herbacea Orchidaceae EndangeredIUCN
14 Calanthe odora Orchidaceae EndangeredIUCN
15 Cassia wallichiana Leguminosae Not EvaluatedIUCN
16 Ceropegia lucida Asclepediaceae Rare, Extinct, Not EvaluatedIUCN
17 Chrysoglossum assamicum Orchidaceae EndangeredIUCN
18 Clematis fulvicoma Rannunculaceae Rare, Not EvaluatedIUCN
19 Coelogyne trinervis Orchidaceae VulnerableIUCN
20 Dendrobium aruanticum Orchidaceae Endangered
21 Dioscorea deltoidea Dioscoreaceae Vulnerable
22 Diospyros cacharensis Ebenaceae Rare Not EvaluatedIUCN
23 Dysoxylum gotadhora Meliaceae Rare, Not EvaluatedIUCN
24 Erythrorchis altissima Orchidaceae EndangeredIUCN, Probably Extinct
25 Eulophia manii Orchidaceae Rare, Endemic, EndangeredIUCN
26 Fissistigma santapaui Annonaceae Endemic, Not EvaluatedIUCN
27 Flacourtii helferi Flacourtiaceae Rare, Not EvaluatedIUCN
28 Goniothalamus simsonii Anonaceae Rare, Not EvaluatedIUCN
29 Goodyera recurva Orchidaceae Endemic, EndangeredIUCN
30 Habenaria trifurcata Orchidaceae Rare, Not EvaluatedIUCN
31 Illigera appendiculata Hernandiaceae Rare, Not EvaluatedIUCN
60
32 Indofevillea khasiana Cucurbitaceae Rare, Not EvaluatedIUCN
33 Lagerstroemia minuticarpa Lythraceae Extinct, EndangeredIUCN
34 Leptomischus wallichii Rubiaceae Rare Not EvaluatedIUCN
35 Liparis cespitosa Orchidaceae Endemic, EndangeredIUCN
36 Liparis delicatula Orchidaceae Rare, Endemic, EndangeredIUCN
37 Liparis vestita Orchidaceae Endemic
38 Livistona jenkinsiana Arecaceae Endangered, Not EvaluatedIUCN
39 Lophopetalum chinense Hamamelidaceae Rare
40 Magnolia baillonii Magnoliaceae Rare, Not EvaluatedIUCN
41 Magnolia caveana Magnoliaceae Rare, Not EvaluatedIUCN
42 Magnolia mannii Magnoliaceae Rare, Endemic, Not EvaluatedIUCN
43 Miliusa dolicantha Annonaceae Rare, Not EvaluatedIUCN
44 Miliusa gustavi Annonaceae Endemic
45 Miliusa insignis Annonaceae Rare
46 Miliusa rabaniana Annonaceae Rare
47 Oldenlandia monocephala Rubiaceae Rare, Not EvaluatedIUCN
48 Oldenlandia scabra Rubiaceae Rare, Not EvaluatedIUCN
49 Ophiorrhiza hispida Rubiaceae Endangered, Not EvaluatedIUCN
50 Ophiorrhiza tingens Rubiaceae Vulnerable, Not EvaluatedIUCN
51 Orophea polycarpa Annonaceae Rare
52 Paphiopedilum spicerianum Orchidaceae Rare, Critically endangeredIUCN
53 Phlogocanthus asperulus Acanthaceae Rare, Not EvaluatedIUCN
54 Smithia grandis Leguminosae Rare, Not EvaluatedIUCN
55 Sterculia khasiana Sterculiaceae Rare
56 Stylidium kunthii Stylidiaceae Rare Not EvaluatedIUCN
57 Symplocos glauca Symplocaceae Rare, Not EvaluatedIUCN
58 Syzygium assamicum Myrtaceae Rare
59 Vanilla pilifera Orchidaceae Rare, EndangeredIUCN
61
Annexure – I List of Orchids of Brahmaputra valley, Assam
(Source: Singh, Phukan & Bujarbarua, 2001 and Barooah & Ahmed, 2014) Genus Species Habitat
Acampe
A. ochracea E
A. papilosa E
A. praemorsa E
A. rigida E
Acanthephippium A. striatum T
A. sylhetense T
Aerides
A. falcate E
A. multiflora E
A. odorata E
A.rosea E
Agrostophyllum
A. brevipes E
A. callosum E
A. planicaule E
Anoectochilus
A. elwesii T
A. grandiflorus T
A. luteus T
A. roxburghii T
A. setaceus T
A. sikkimensis T
A. tortus T
Anthogonium A. gracile T
Aphyllorchis A. montana T
Apostasia
A. nuda T
A. odorata T
A. wallichii T
Appendicula A. cornuta E
Arachnis A. flos-aeris E
A. labrosa E
62
Arundina A. graminifolia T
Ascocentrum A. ampullaceum E
A. curvifolium E
Biermannia B. bimaculata E
Brachycorythis B. helferi T
B. iantha T
Bryobium B. pudicum E
Bulbophyllum
B. affine E
B. capillipes E
B. careyanum E
B. cariniflorum E
B. crassipes E
B. cylindraceum E
B. delictescens E
B. ellasonotum E
B. forrestii E
B. guttulatum E
B. helenae E
B. hookeri E
B. iners E
B. muscicola E
B. obrienianum E
B.odoratissimum E
B. pectinatum E
B. polyrrhizum E
B. psychoon E
B. pumilo E
B. reptans E
B. retusiusculum E
B. sarcophyllum E
B. secundum E
63
B. tricorne E
B. triste E
B. wallichii E
Calanthe
C. angusia T
C. biloba T
C. clavata T
C. densiflora T
C.herbacea T
C. lyroglossa T
C. mannii T
C. masuca T
C. odora T
C. sylvatica T
C. triplicate T
C. vaginata T
Cephalanthera C. longifolia T
Cephalantheropsis C. gracilis T
C. longipes T
Ceratostylis
C. himalaica E
C. subulata E
C. teres E
Cheirstylis C. griffithii E
Cleisocentron C. trichomum E
Chiloschista C. lunifera E
Chrysoglossum C. assamicum T
Cleisocentron C. pallens E
Cleisostoma
C. appendiculatum E
C. arietinum E
C. filiforme E
C. loratum E
C. paniculatum E
64
C. racemiferum E
C. striatum E
C. subulatum E
Coelogyne
C. assamica E
C. barbata E
C. fimbriata E
C. griffithii E
C. nitida E
C. ovalis E
C. prolifera E
C. punctulata E
C. rossiana E
C. schultesii E
C. stricta E
C. suaveolens E
C.tomentosa E
C. trinervis E
C. viscose E
Collabium C. assamicum E
Conchidium C. muscicola E
Corymborkis C. veratrifolia T
Cremastra C. appendiculata T
Crepidium C. biauritum T
C. mackinnonii T
Cryptostylis C. arachnites T
Cymbidium
C. aloifolium E
C. assamicum E
C. bicolour E
C. cochleare E
C. dayanum E
C. eburneum E
65
C. elegans E
C. hookerianum E
C. iridioides E
C. lancifolium E
C. macrorhizon E
C. mastersii E
Cyrtosia C. javanica T
C. lindleyana T
Dendrobium
D. acinaciforme E
D. aduncum E
D. anceps E
D. angulatum E
D. aphyllum E
D. assamicum E
D. bensoniae E
D. bicameratum E
D. chrysanthum E
D. chryseum E
D. chrysotoxum E
D. crepidatum E
D. cretaceum E
D. cumulatum E
D. densiflorum E
D. devonianum E
D. eriiflorum E
D. falconeri E
D. farmer E
D. fimbriatum E
D. formosum E
D. gibsonii E
D. griffithianum E
66
D. heterocarpum E
D. hookerianum E
D. infundibulum E
D. jenkinsii E
D. keithii E
D. kentrophyllum E
D. lindleyi E
D. lituiflorum E
D. mannii E
D. miserum E
D. moschatum E
D. nathanielis E
D. nobile E
D. praciflorum E
D. polyanthum E
D. perula E
D. podagraria E
D. pulchellum E
D. salaccense E
D. spatella E
D. stuposum E
D. sulcatum E
D. terminale E
D. transperans E
D. wardianum E
D. willamsonii E
Didymoplexis D. himalaica T
D. pallens T
Dienia D. ophrydis T
Doritis D. pulcherrima E
Epigenium E. ampulum E
67
Epipogium E. indicum E
E. roseum E
Eria
E. alba E
E. amica E
E. apertiflora E
E. biflora E
E. bractescens E
E. carinata E
E. clavicaulis E
E. javanica E
E. excavate E
E. lasiopetala E
E. muscicola E
E. paniculata E
E. pannea E
E. pudica E
E. pumila E
E. sharmae E
E. spicata E
E. stricta E
E. tomentosa E
Erythrodes E. hirsute T
Erythrorchis E. altissima T
Eulophia
E. bicallosa T
E. bracteosa T
E. candida T
E. dabia T
E. graminea T
E. herbacea T
E. kamarupa T
E. mannii T
68
E. nuda T
E. spectabilis T
E. zollingeri T
Flickingeria F. fugax E
F. macraei E
Galeola G. altissima E
Gastrochilus G. dasypogon
G. inconspicuus
G. obliquus
E
E
E
Geodorum
G. densiflorum E
G. laxiflorum E
G. recurvum E
Goodyera
G. cordata T
G. foliosa T
G. hispida T
G. procera T
G.recurva T
G. repens T
G. viridiflora T
Gymnadenia G. orchidis E
Habenaria
H. commelinifolia T
H. digitata T
H. furcifera T
H. longifolia T
H. mandersii T
H. marginata T
H. plantaginea T
H. reniformis T
H. stenopetala T
H. trifurcata T
Herminium H. lanceum E
69
Herpysma H. longicaulis E
Hetaeria
H. affinis T
H. anomala T
H. rubens E/T
Kingidium K. deliciosum E
K. taenialis T
Liparis
L. assamica E
L. bootanensis E
L. caespitosa E
L. delicatula E
L. distans E
L. elliptica E
L. luteola E
L. mannii E
L. odorata E
L. paradoxa T
L. petiolata T
L. plantaginea E
L. vestita E
L. viridiflora E
Luisia
L. bracystachys E
L. macrotis E
L. microptera E
L. platyglossa E
L. psyche E
L. trichorhiza E
L. tristis E
L. zeylanica T/E
Malaxis M. acuminata T
M. latifolia T
Micropera M. obtuse E
70
M. pallida E
M. rostrata E
Neogyna N. gardneriana E
Nephelaphyllum N. cordifolium T
Nervalia
N. aragoana E
N. Juliana T
N. plicata T
Oberonia
O. acaulis E
O. anthropophora E
O. bicornis E
O. emarginata E
O. ensiformis E
O. falconeri E
O. jenkinsiana E
O. mannii E
O. mucronata E
O. myriantha E
O. obcordata E
O. pachyrachis E
O. pyrulifera E
Odontochilus O. lanceolatus E
O. tortus E
Ornithochilus O. difformis E
Otochilus
O. albus E
O. fuscus E
O. lancilabius E
O. porrectus E
Pachystoma P. pubescens T
Panisea P. demissa E
P. tricallosa E
Paphiopedilum P. venustum T
71
P. villosum T
Papilionanthe
P. teres E
P. uniflora E
P. vandarum E
Pecteilis P. susannae T
P. triflora T
Pelatantheria P. insectifera E
Pennilabium P. proboscideum E
Peristylus
P. constrictus T
P. goodyeroides T
P. hamiltonianus T
P. parishii T
P. prainii T
Phaius
P. flavus T
P. mishmensis T
P. tankervilliae T
Phalaenopsis
P. cornucervi E
P. mannii E
P. parishii E
P. pulcherrima T
Pholidota
P. articulate E
P. bracteata E
P. chinensis E
P. convallariae E
P. imbricate E
P. pallida E
P. wattii E
Phreatia P. elegans E
Pinalia
P. acervata E
P. amica E
P. excavate E
72
P. stricta E
Platanthera P. clavigera T
Podochilus P. cultratus E
Pomatocalpa P. mannii E
P. spicatum E
Pteroceras P. teres E
Renanthera R. imschootiana E
Rhinerrhiza R. divitiflora E
R. freemanii E
Rhynchostylis R. retusa E
Robiquetia R. succisa E
Saccolabiopsis S. pusilla E
Smitinandia S. micrantha E
Satyrium S. nepalense T
Schoenorchis S. gemmata E
Spathoglotis S. plicata T
Spiranthes S. sinensis T
Stereochilus S. ringens E
Stichorkis
S. distans E
S. elliptica E
S. mannii E
S. vestita E
S. viridiflora E
Sunipia S. cirrhata E
S. virens E
Taeniophyllum T. glandulosum E
Tainia T. latifolia T
T. viridifusca T
Thelasis T. pygmaea E
Thrixspermum T. centipede E
T. trichoglottis E
73
Thunia T. alba T/E
Trichotosia T. pulvinata E
Tropidia T. angulosa T
T. curculigoides T
Tylostylis T. discolour E
Uncifera U. acuminata E
U. obtusifolia E
Vanda
V. bicolour E
V. coerulea E
V. coerulescens E
V. cristata E
V. stangeana E
V. tessellate E
V. testacea E
Vandopsis V. undulate E
Vanilla
V. borneensis T
V. pilifera T
V. walkeriae T
Zeuxine
Z. assamica T
Z. cordata T
Z. flava T
Z. goodyeroides T
Z. gracilis T
Z. longilabris T
Z. membranacea T
Z. nervosa T
Z. strateumatica T
E – Epiphyte, T - Terrestrial
Note: The names of the plant taxa mentioned in the appendix and annexure are subjected
to recent nomenclatural changes.